diff --git a/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/PersonValueBuilder.scala b/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/PersonValueBuilder.scala
index 2649c19e57fb8ed8ff57fa733a4a9b0e5e10aebc..e4f82ade3a1eb72f5b034ce6bf7b75df2150cf55 100644
--- a/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/PersonValueBuilder.scala
+++ b/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/PersonValueBuilder.scala
@@ -21,6 +21,7 @@
 package ch.swisscollections.alphabeticbrowse.stream.functions
 
 import ch.swisscollections.alphabeticbrowse.analyze.AnalyzeWrapper
+import ch.swisscollections.alphabeticbrowse.stream.functions.SubjectValueBuilder.logger
 import ch.swisscollections.alphabeticbrowse.utilities.CombineWithGndIdAndVariations.cleanup
 import ch.swisscollections.alphabeticbrowse.utilities.{CombineWithGndIdAndVariations, MongoClient, XmlHelper}
 import org.apache.logging.log4j.scala.Logging
@@ -509,6 +510,7 @@ object PersonValueBuilder extends Function3[String,String,GndValuesProvider,List
       case Success(value) => value
       case Failure(exception) =>
         logger.error(s"""exception in PersonValueBuilder: ${exception.getMessage}""")
+        logger.error(s"""exception in PersonValueBuilder: ${exception.getStackTrace.mkString("Array(", ", ", ")")}""")
         List() //handover en empty String which is filtered out in the next operator
 
     }
diff --git a/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/SubjectValueBuilder.scala b/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/SubjectValueBuilder.scala
index 833013c178cdb90f924d6d9b6fce8c16ccaaff9a..074a765e9f5fc07044e8463966682c0535616ba7 100644
--- a/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/SubjectValueBuilder.scala
+++ b/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/SubjectValueBuilder.scala
@@ -286,6 +286,8 @@ object SubjectValueBuilder extends Function3[String,String,GndValuesProvider,Lis
       case Success(value) => value
       case Failure(exception) =>
         logger.error(s"""exception in SubjectValueBuilder: ${exception.getMessage}""")
+        logger.error(s"""exception in PersonValueBuilder: ${exception.getStackTrace.mkString("Array(", ", ", ")")}""")
+
         List() //handover en empty String which is filtered out in the next operator
 
     }
diff --git a/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/TitleValueBuilder.scala b/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/TitleValueBuilder.scala
index 1d0f2e321eb7b2faa9f285a6ff2bc3da888940f8..5b4c552e4c629cb4bd769a22ed90fd80156e9a8e 100644
--- a/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/TitleValueBuilder.scala
+++ b/src/main/scala/ch/swisscollections/alphabeticbrowse/stream/functions/TitleValueBuilder.scala
@@ -23,6 +23,7 @@
 package ch.swisscollections.alphabeticbrowse.stream.functions
 
 import ch.swisscollections.alphabeticbrowse.analyze.AnalyzeWrapper
+import ch.swisscollections.alphabeticbrowse.stream.functions.SubjectValueBuilder.logger
 import ch.swisscollections.alphabeticbrowse.utilities.CombineWithGndIdAndVariations.cleanup
 import ch.swisscollections.alphabeticbrowse.utilities.{CombineWithGndIdAndVariations, MongoWrapper, XmlHelper}
 import org.apache.logging.log4j.scala.Logging
@@ -67,6 +68,7 @@ object TitleValueBuilder extends Function3[String,String,GndValuesProvider,List[
       case Success(value) => value
       case Failure(exception) =>
         logger.error(exception.getMessage)
+        logger.error(s"""exception in PersonValueBuilder: ${exception.getStackTrace.mkString("Array(", ", ", ")")}""")
         List() //handover en empty String which is filtered out in the next operator
 
     }